In fragment get value from editText and do calculation

Question

I just added my first fragment into my app. Now I want to do some calculation there. It has 4 editText fields and a Calculate button.

If I do a toast for the button, the toast is shown!

But there is no result shown.

What am I doing wrong?

import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;

import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;


public class MessageFragment extends Fragment {


    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_message, container, false);
    }


    @Override
    public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

        view.findViewById(R.id.bt_calculate).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                Toast.makeText(getActivity(), "Hi, connection is working!!!", Toast.LENGTH_SHORT).show();

                EditText input1 = (EditText) view.findViewById(R.id.et_input1);
                EditText input2 = (EditText) view.findViewById(R.id.et_input2);
                EditText input3 = (EditText) view.findViewById(R.id.et_input3);
                EditText input4 = (EditText) view.findViewById(R.id.et_inputSp);
                try {
                    int a = Integer.parseInt(input1.getText().toString());
                    int b = Integer.parseInt(input2.getText().toString());
                    int c = Integer.parseInt(input3.getText().toString());
                    int d = Integer.parseInt(input4.getText().toString());
                    int calc = (a * 10) + (b * 20) + (c * 30) + (d * 15);
                    TextView answer = (TextView) view.findViewById(R.id.tv_result);
                    answer.setText("" + calc);
                } catch (Exception e) {
                    //Textfield empty
                }

            }

        });
    }
}

And here is my XML File. The texts are in German, I hope you understand everything. Otherwise please ask me.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="@android:color/white">

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="wrap_content"
        android:layout_height="39dp"
        android:layout_centerHorizontal="true"
        android:text="Handelsschiff Event Rechner"
        android:textColor="#F44336"
        android:textSize="24sp" />

    <EditText
        android:id="@+id/et_input1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/tv_title"
        android:ems="10"
        android:hint="3. Klasse Marken"
        android:inputType="number" />

    <EditText
        android:id="@+id/et_input2"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/et_input1"
        android:ems="10"
        android:hint="2. Klasse Marken"
        android:inputType="number" />

    <EditText
        android:id="@+id/et_input3"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/et_input2"
        android:ems="10"
        android:hint="1. Klasse Marken"
        android:inputType="number" />

    <EditText
        android:id="@+id/et_inputSp"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@+id/et_input3"
        android:layout_alignParentStart="true"
        android:hint="SP Klasse Marken"
        android:inputType="number" />

    <TextView
        android:id="@+id/tv_result"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="311dp"
        android:hint="Hinweis" />

    <Button
        android:id="@+id/bt_calculate"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_below="@+id/et_inputSp"
        android:layout_alignParentStart="true"
        android:layout_centerHorizontal="true"
        android:layout_gravity="center_horizontal"
        android:layout_marginStart="154dp"
        android:layout_marginTop="154dp"
        android:text="Calculate" />

</RelativeLayout>

I just clicked around and hit the textView where the result should be. And when I click, the correct result is shown. Why that? — Gregor Knapp, Sep 06 '20 at 00:04
Does this answer your question? [Get edittext value from fragment](https://stackoverflow.com/questions/25134645/get-edittext-value-from-fragment) — Anuj Kumar, Sep 06 '20 at 02:08

User9211 · Accepted Answer · 2020-09-06T02:04:41.890

1

Do it like this -

Initialize your views in the beginning and to access them inside onclick, make them final.

And we don't need to cast views like (Edittext) findViewById(R.id.editText1).

public void onViewCreated(@NonNull View view, @Nullable Bundle savedInstanceState) {
        super.onViewCreated(view, savedInstanceState);

                final EditText input1 = view.findViewById(R.id.et_input1);
                final EditText input2 = view.findViewById(R.id.et_input2);
                final EditText input3 = view.findViewById(R.id.et_input3);
                final EditText input4 = view.findViewById(R.id.et_inputSp);
                final TextView answer = view.findViewById(R.id.tv_result);

        view.findViewById(R.id.bt_calculate).setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {

                            Toast.makeText(getActivity(), "Hi, connection is working!!!", Toast.LENGTH_SHORT).show();

            try {
                int a = Integer.parseInt(input1.getText().toString());
                int b = Integer.parseInt(input2.getText().toString());
                int c = Integer.parseInt(input3.getText().toString());
                int d = Integer.parseInt(input4.getText().toString());
                int calc = (a * 10) + (b * 20) + (c * 30) + (d * 15);
                answer.setText("" + calc);
            } catch (Exception e) {
                //Textfield empty
            }
            }
        });

For input: a=2,b=2,c=2,d=2 Output: 150

edited Sep 06 '20 at 02:04

answered Sep 06 '20 at 01:53

User9211

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THANKS YOU VERY MUCH!!!! Everything is working now! :-) – Gregor Knapp Sep 06 '20 at 07:16
Is there a possibility to display the result as: 1.234.567 and not 1234567 ??? – Gregor Knapp Sep 06 '20 at 10:05
for what value? if that's a string, you can use loop and avoid those decimals. – User9211 Sep 06 '20 at 10:12
the result calc in my fragment. – Gregor Knapp Sep 06 '20 at 11:58
what's input and what operation? For example int calc = (a * 10) + (b * 20) + (c * 30) + (d * 15); ..answer will be an int. – User9211 Sep 06 '20 at 12:01
User may enter values that can be int like 10 or double like 10.5 ..so it would be better to declare all variables as double(not int) if that's what you're trying to do – User9211 Sep 06 '20 at 12:11
Let us [continue this discussion in chat](https://chat.stackoverflow.com/rooms/221043/discussion-between-gregor-knapp-and-user9211). – Gregor Knapp Sep 06 '20 at 12:16

In fragment get value from editText and do calculation

1 Answers1